jw-pkg/src/python/jw/pkg/cmds/projects/lib/templates.py

import textwrap

from typing import Any, Iterable, TypeAlias, TypeGuard

TupleList: TypeAlias = Iterable[tuple[str, str]]
ListDict: TypeAlias = dict[str, list[str]]
StrDict: TypeAlias = dict[str, str]
RenderValues: TypeAlias = ListDict | StrDict | TupleList

def is_str_dict(values: object) -> TypeGuard[StrDict]:
    if not isinstance(values, dict):
        return False
    for key, val in values.items():
        if not isinstance(key, str):
            return False
        if not isinstance(val, str):
            return False
    return True

def is_list_dict(values: object) -> TypeGuard[ListDict]:
    if not isinstance(values, dict):
        return False
    for key, val in values.items():
        if not isinstance(key, str):
            return False
        if isinstance(val, str):
            continue
        if not isinstance(val, list):
            return False
        for entry in val:
            if not isinstance(entry, str):
                return False
    return True

def is_tuple_list(values: object) -> TypeGuard[TupleList]:
    if not isinstance(values, list):
        return False
    for item in values:
        if not isinstance(item, tuple):
            return False
        if not len(item) == 2:
            return False
        if not isinstance(item[0], str):
            return False
        if not isinstance(item[1], str):
            return False
    return True

def render_values_to_list_dict(values: object) -> ListDict:

    def __tuple_list_to_dict(src: TupleList) -> ListDict:
        ret: ListDict = {}
        for key, val in src:
            entry = ret.setdefault(key, [])
            entry.append(val)
        return ret

    if is_list_dict(values):
        ret: ListDict = {}
        for key, val in values.items():
            # -- A string value is treated as a list with a single element;
            # merging it unconverted would split it into characters
            ret[key] = val if isinstance(val, list) else [val]
        return ret
    if is_tuple_list(values):
        return __tuple_list_to_dict(values)
    raise Exception('Unsupported template value layout')

def merge_values(*values: RenderValues) -> ListDict:
    ret: ListDict = {}
    for rhs in values:
        rhs_dict = render_values_to_list_dict(rhs)
        for key, val in rhs_dict.items():
            entry = ret.setdefault(key, [])
            entry += val
    return ret

def format_list_dict(
    template: str, values: ListDict | dict[str, str], li_quote: bool, li_delimiter: str
) -> str:

    def __format_value(val: Any) -> str:
        if not li_quote:
            return str(val)
        return f'"{val}"'

    fmt_dict: dict[str, str] = {}
    for key, value in values.items():
        if isinstance(value, (list, tuple)):
            fmt_dict[key] = li_delimiter.join(map(__format_value, value))
        elif isinstance(value, str):
            fmt_dict[key] = value

    ret: list[str] = []
    parts = template.splitlines(keepends = True)

    for line in parts:
        for key, value in fmt_dict.items():
            marker = '{' + key + '}'
            if marker in line:
                indent = line[:line.index(marker)]
                value = str(value).replace('\n', '\n' + indent)
                line = line.replace(marker, value)
        ret.append(line)

    return ''.join(ret)

def format_lines(
    template: str, values: list[RenderValues], li_quote: bool, li_delimiter: str
) -> str:
    return format_list_dict(template, merge_values(*values), li_quote, li_delimiter)

_templates = {
    'pkg-config':
    """\
        prefix = {prefix}
        exec_prefix = {{prefix}}
        includedir = {{prefix}}/include
        libdir = {{exec_prefix}}/lib

        Name: {name}
        Description: {description}
        Version: {version}
        """,
    'pyrightconfig.json':
    """\
        {
          "extends": {base},
          "include": [
            {include}
          ],
          "exclude": [
            "**/__pycache__",
            "**/.pytest_cache",
            "**/.mypy_cache",
            "**/.ruff_cache",
            "**/.venv",
            "**/build",
            "**/dist"
          ],
          "extraPaths": [
            {extra_paths}
          ],
          "typeCheckingMode": "basic",
          "pythonPlatform": "Linux"
        }
        """,
}

def tmpl_render(
    template_name: str,
    values: list[RenderValues],
    li_quote: bool = False,
    li_delimiter: str = '\n',
    search_path: list[str] | None = None,
) -> str:

    def __format(template: str) -> str:
        return format_lines(
            template,
            values,
            li_quote = li_quote,
            li_delimiter = li_delimiter,
        )

    for d in search_path if search_path else []:
        path = d + '/' + template_name
        try:
            with open(path, 'r') as f:
                template = f.read()
                return __format(template)
        except FileNotFoundError:
            pass

    raw = _templates.get(template_name, None)
    if raw is None:
        raise Exception(f'Failed to find template "{template_name}"')
    return __format(textwrap.dedent(raw))